package main.chapter5.reflection;/**
 * @Author xy
 * @Date 2020/6/16 21:23
 * @Description
 */

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Objects;
import java.util.Scanner;

/**
 * 文件名称： main.chapter5.reflection.ReflectionTest.java</br>
 * 初始作者： xy</br>
 * 创建日期： 2020/6/16 21:23</br>
 * 功能说明： TODO <br/>
 * =================================================<br/>
 * 修改记录：<br/>
 * 修改作者        日期       修改内容<br/>
 * ================================================<br/>
 * Copyright (c) 2020-2021 .All rights reserved.<br/>
 */
public class ReflectionTest {
    public static void main(String[] args) throws ClassNotFoundException {
        String name;
        if(args.length > 0){
            name = args[0];
        }else {
            Scanner in  = new Scanner(System.in);
            System.out.println("Enter class name (e.g. java.util.Date): ");
            name = in.next();
        }
        Class cl = Class.forName(name);
        Class superCl = cl.getSuperclass();
        String modifiers = Modifier.toString(cl.getModifiers());
        if(modifiers.length()>0){
            System.out.print(modifiers+" ");
        }
        System.out.print("class "+name);
        if(superCl != null && superCl != Objects.class){
            System.out.print(" extends "+superCl.getName());
        }
        System.out.print("\n{\n");
        printConstructors(cl);
        System.out.println();
        printMethods(cl);
        System.out.println();
        printFields(cl);
        System.out.println("}");

    }

    /**
     * print all constructors of a class
     * @param cl
     */
    public static void printConstructors(Class cl){
        Constructor[] constructors = cl.getDeclaredConstructors();

        for(Constructor c : constructors){
            String name = c.getName();
            System.out.print("  ");
            String modifiers = Modifier.toString(c.getModifiers());
            if(modifiers.length()>0){
                System.out.print(modifiers+" ");
            }
            System.out.print(name+"(");

            //print parameter types
            Class[] paramTypes = c.getParameterTypes();
            for(int j=0;j<paramTypes.length;j++){
                if(j>0){
                    System.out.print(", ");
                }
                System.out.print(paramTypes[j].getName());
            }
            System.out.println(");");
        }
    }

    /**
     * Prints all methods of a class
     * @param cl
     */
    public static void printMethods(Class cl){
        Method[] methods = cl.getDeclaredMethods();

        for(Method m : methods){
            Class retType = m.getReturnType();
            String name = m.getName();
            System.out.print("  ");

            //print modifiers,return type and method name
            String modifiers = Modifier.toString(m.getModifiers());
            if(modifiers.length()>0){
                System.out.print(modifiers+" ");
            }
            System.out.print(retType.getName()+" "+ name + "(");

            Class[] paramTypes = m.getParameterTypes();
            for(int j=0; j<paramTypes.length; j++){
                if (j>0){
                    System.out.print(", ");
                    System.out.print(paramTypes[j].getName());
                }
            }
            System.out.println(");");
        }
    }


    /**
     * Prints all fields of a class
     * @param cl
     */
    public static void printFields(Class cl){
        Field[] fields = cl.getDeclaredFields();
        for (Field f : fields){
            Class type = f.getType();
            String name = f.getName();
            System.out.print("  ");
            String modifiers = Modifier.toString(f.getModifiers());
            if(modifiers.length()>0){
                System.out.print(modifiers + " ");
            }
            System.out.println(type.getName()+ " " +name + ";");
        }

    }


}
